FR2483115A1 - DEVICE FOR COLLECTING LIQUIDS AND PURGE GASES IN AN INSTALLATION COMPRISING SUBSTANCES WHICH MAY PRESENT CERTAIN RADIOACTIVITY - Google Patents

Abstract

THE INVENTION RELATES TO A DEVICE FOR COLLECTING PURGE LIQUIDS AND GASES IN AN INSTALLATION CONTAINING RADIOACTIVE SUBSTANCES. THE SELF-CONTAINED AND MOBILE COLLECTION DEVICE INCLUDES A SMALL-SIZED REMOVABLE AND TRANSPORTABLE SPEAKER 5, A PURGE 2 CLOSURE Means that can be operated from the exterior of the enclosure 5, a mobile unit 7 for suction and collection of liquids AND PURGE GAS AND A FLEXIBLE PIPING 6 FOR CONNECTION BETWEEN THE ENCLOSURE 5 AND THE MOBILE SUCTION AND COLLECTION UNIT 7. THE INVENTION APPLIES IN PARTICULAR TO THE BLEEDING OF THE COOLING CIRCUIT WHEN STOPPED. A PRESSURIZED WATER NUCLEAR REACTOR.

Description

The invention relates to a device for collecting liquids and

  purge gas in an installation containing substances which may

  feel some radioactivity, such as the cooling circuit

  shutdown of a pressurized water nuclear reactor.

  In a nuclear power plant, it is necessary to be able to purge

  circuits which are not used continuously, such as cir-

  cooling off and, in general, all

circuit elements that are isolatable.

  It is also necessary to be able to purge

  able to contain liquids or gases contaminated by the substances

  radioactive material from the reactor core.

  This purge operation can take place during cold shutdowns and requires certain precautions because the liquids or gases remaining in the circuits that are purged are generally contaminated.

  by radioactive substances coming from the reactor core.

  Currently connected collection networks are used directly

  piping and equipment that is purged. The networks are equipped with manholes allowing visual inspection of the purge flow and are permanently connected to the circuits on which they are connected.

  must collect liquids and purge gases.

  The points of the pipe where the purges are to be carried out are numerous and distributed all along the circuit to be purged.

  Purge collection is usually complex and of great length.

  The pipes forming this purge collection network are

  heavily contaminated since fluids circulate very rarely

  radioactive products are thus formed in this way.

  légiée. Some of these pipes are so contaminated that it is necessary to

  provide for their replacement during the life of the plant.

  When the purge of the liquids contained in the pipe or the equipment to be purged is completed, the section of pipe that has been purged is filled with air which, when filling the piping escapes

  vents by drawing in a small amount of liquid containing

  dioactifs. This air must be sent to a front phase separator

  to release the gaseous phase into the atmosphere of the building.

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  Contaminated fluids collected are sent to a facility

  treatment of contaminated effluents which eliminates

radioactive products.

  The facilities for collecting liquids and purge gases in the equipment circuits of nuclear power plants are therefore very

  complex and bulky and increase the cost of constructing

nuclear.

  The object of the invention is therefore to propose a device for

  collection of liquids and purge gases in an installation containing substances that may have some radioactivity and

  closable means of purging distributed in different places on the

  this device must prevent the use of networks

  complex pipelines permanently connected to the installation.

  For this purpose, the autonomous and mobile collection device is con-

  located by: - a removable and transportable enclosure of small size connectable by means of purging the installation so that the internal volume of

  the enclosure is isolated from the outside environment.

  a means for closing the purging means operable from the outside

  enclosure to isolate or connect the interior of the enclosure

  encircled with the installation to be purged, - a mobile suction and collection unit for liquids and purge gases

  comprising at least one collection reservoir, a suction means for

  the interior of this tank, means for evacuating gases to the atmosphere and a connecting element for evacuation of the purge liquids to a treatment plant,

  - and a flexible connection pipe between the enclosure and the unit of

piration and collection.

  We will now describe, without limitation, in referring

  annexed to the figures, an embodiment of a recom-

  collection of liquids and purge gases that can be used, for example, in a

  nuclear pressurized water trench, for the purging of the cooling circuit

reactor shutdown at shutdown.

  Figure 1 shows an elevational view with partial section

of the device according to the invention.

  FIG. 2 represents an enlarged sectional view of the enclosure

  connecting the device to a means for purging the cooling circuit

reactor discharge.

  FIG. 1 shows a pipe section 1 of the cooling circuit of the shutdown reactor on which is mounted bypassing a means / purge constituted by a bypass piping element 2 and

a valve 3.

  An enclosure 5 of small size is sealingly connected to the pipe 2 downstream of the valve 3, this enclosure 5 allowing the connection of the purge collection device by means of purge of the

pipeline 1.

  The enclosure 5 is connected via a flexible pipe 6 to a suction and purge collection unit 7 mobile on

the ground 8 of the reactor building.

  This suction and collection unit consists of a chain

  riot 9 on which is fixed a tank 10, a separation unit and

  purge 11 and a vacuum pump 12.

  The inner volume of the tank 10 is separated into two parts

  by a flexible membrane 15, the upper part of the container being

  connected by a pipe 16 to the vacuum pump 12 and the lower part

  being connected to the lower part of the phase separator II by means of a

nalisation 18.

  A valve 43 allows the introduction of air into the container 10

  to break the vacuum in the upper part of this container.

  A valve 20 makes it possible to close the communication between the separator

  He and the lower part of the container 10.

  At the top of the phase separator 11 is placed a gas purge device 24 communicating with the interior of the container.

  for the purging of gases separated from liquids by means of a

be 25.

  The flexible pipe 6 is extended inside the gas separator by a vertical stick 27 allowing the separation of the gas and the liquid by pouring of this liquid into the bottom of the separating container.

phases II.

  In FIG. 2, the enclosure 5 for connecting the device for collecting the purge fluids with the purging means is shown.

  of the pipe 1 of the reactor cooling circuit.

  On the pipe 2 constituting the purging means of the pipe section 1, is fixed a plate 30 having a bearing area 31 on which can be fixed in a sealed manner a lip 32 of flexible material constituting the upper extreme portion of the speaker 5. A ring

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  clamping device 33 makes it possible to fix the enclosure 5 on the base

  pipe 2 constituting a purging means of the pipe 1.

  The enclosure 5 is made of flexible or rigid material comprising

  transparent areas to monitor the evolution of the opera-

  purge. The enclosure 5 is provided with two handling gloves 34 fixed

  in a sealed manner in openings of the enclosure 5.

  The end of the pipe 2 disposed inside the enclosure

  5 when the purge collection device is connected to this pipe comprises a sealing device which can be actuated by a

  operator from outside the enclosure 5 thanks to the gloves 34.

  This sealing device is supported on a shoulder-

  35 forming the lower part of the pipe 2 and comprises a sleeve 36 and a cap 38 on which the upper part of the nut 37

comes in support.

  A seal 40 is interposed between the plug 38 and

the shoulder 35.

  Blocking and unblocking of the watertight closure of the pipe

  2 can be achieved by the operator by means of a tool 41 placed in the

  the enclosure 5 on a filtering grid 42 serving both to

  support for the tool and filter element of the purge liquids,

ntering in the enclosure 5.

  At its lower part, the enclosure 5 has an exit 45

related to flexible driving 6.

  Inside the chamber 5 is also disposed a spray boom 48, for decontaminating the elements of the closure device of the pipe 2 and the decontamination of the enclosure 5

  and all the devices that this enclosure can contain.

  The O-pipe 48 carrying spray nozzles 50 is

  linked to a pipe 51 allowing its feeding into a solution of de-

  contamination contained in a reservoir not shown and sent under

  pressure inside the pipe 51.

  We will now describe a liquid collection operation and

  - gas from the purging of a cooling pipe of a reaction

nuclear power plant.

  The whole thing is brought close to a

  pick 2 constituting a means of purging a section of the pipe.

  Moving the equipment is easy thanks to the

248 3,115

  carriage 9 which allows the transport of all the elements constituting this device, the enclosure 5 then being in a position not connected to

a purge line 2.

  The length of the pipe 6 is approximately 5 meters, which makes it possible, by arranging the carriage at the desired location, to always reach

  the purges of the cooling circuit of the reactor at a standstill.

  The operator has inside the glove box a

  seems to be a complete replacement for the closure of line 2, this

  seems to be a replacement with a plug such as 38, a piece of

  such as 40 and a nut such as 37.

  A dismantling tool has also been placed in the enclosure.

  the closing element of the pipe, such as 41.

  The purge pipe 2 is closed by a complete assembly as shown in FIG. 20

  The enclosure 5 is then provided with handles for its handling.

  in position on the support zone 31 of the plate 30 so that the flexible lip 32 is applied on this support zone 31o is then made the junction between the enclosure 5 and the pipe

  2 thanks to quick release clamp 33.

  The operator dismounts then, using the gloves 34 and the tool

  41 the closure device in position on the terminal end of the con-

  The operator then places the nut 37 and the plug 38 as well as the

  seal 40 on the filtering grid 42 serving as storage for these elements.

closures.

  1 The valve 3 is then opened allowing the purging of the

trunk / channel.

  If the difference in level between the purge point and the reservoir

  see 10 is sufficient, it is not necessary to start the pump.

  vacuum pump which allows a suction in the lower part

  of the collecting tank 10 via the flexible membrane 15.

  In the opposite case, it is necessary to carry out this startup of the pump

  12, which can be done with a control box located near

  of the enclosure 5 constituting a glove box or within it.

the latter.

  The enclosure 5 being partly transparent, it is possible to follow the

  purging of the pipeline by simple visual control.

  The purge liquid flows through the purge pipe 2 to the

  5, is filtered by the gate 42 and leaves the enclosure 5

  through the outlet port 45 in communication with the conduit 6.

  The purge liquid flows into a phase separator 11,

  after crossing the line 6.

  The liquid collected at the bottom of this phase separator is then driven towards the lower part of the tank 10 either by the suction due to the creation of the vacuum in the upper part of the tank 10, or by natural flow if there is a sufficient difference in level between the pipe in which the purge is carried out

and the reservoir 10.

  When the purging is complete, pipe 2 is closed with the

  new closure element assembly contained in the enclosure 5.

  The assembly that was dismounted before the start of the operation

  The purge is decontaminated by means of the spray boom 48.

  When all the piping is purged and we begin the replacement

  pleating of this piping is performed the collection of air filling the pipe by fixing the enclosure 5 at the end of the pipe on a ventilation pipe which has a closure identical to that of

purge pipes.

  As the piping fills, the stale air is forced from it through the vent pipe to the enclosure, and thence into the flexible pipe 6 and into the phase separator 11. In the phase separator 11, the air-entrained liquid falls into the lower part of the container, however, as the air after passing through the filter wall exits through the vent pipe 24

  the closing valve has been opened. The air is therefore rejected in the

  mosphere of the building while the contaminated liquid is removed from the

  same way as the purge liquid which is collected in the lower part

  tank 10 before being sent to a retirement facility.

ment.

  For this, at the end of a purge collection operation and

  vents in the pipeline, the collection device is brought

  of an effluent treatment circuit, to bring these ef-

  fluent to a treatment and decontamination unit.

  But the invention is not limited to the embodiment that comes

  to be described, it includes all the variants.

  It is thus possible to imagine a use of a remote handling device to replace the gloves of the enclosure 5, which can be

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  provide another method of fixing the enclosure 5 on the pipe 2 that the fastening mode which has been envisaged this fixing can be done by screwing or by bayonet assembly

  It can be seen that the main advantages of the device according to

  are to avoid the use of a complex and cumbersome fixed circuit and to make it possible to carry out the liquid collection operations

  and purge gas in the pipeline quickly and safely.

  Another advantage of the device that has been described is that there

  no pump in the purge circuit and that the suction of substances

  these contaminated is done through a flexible waterproof membrane.

  Finally, the device according to the invention can be used not only

  in the case of purging the pipelines of a nuclear reactor

  pressurized water but also in the case of purging any

  or equipment that may contain radioactive substances.

Claims (6)

  1.- Device for collecting liquids and purge gases in an installation containing substances that may have a certain radioactivity comprising closable means of purging distributed at different locations on the installation, characterized in that the autonomous collection device and mobile is constituted by   a removable and transportable enclosure (5) of small size   by means of purging (2) of the installation so that the volume of   the enclosure (5) is isolated from the outside environment.   a means for closing (36, 37, 38, 40) the purge means (2)   from the outside of the enclosure (5) to isolate or   nication inside the enclosure (5) with the installation to be purged, - a mobile unit for suction and collection of liquids and purge gases comprising at least one collection tank (10), a suction means ( 10) inside this tank (10), a means (11) for evacuating gases to the atmosphere, and a connecting element for discharging purge liquids to a treatment plant,   - and a flexible pipe (6) connecting the enclosure (5) and ltu-   aspiration and collection unit (10-11).   2. A collection device according to claim 1, characterized in that the mobile unit for suction and collection of liquids and gases comprises, on a transport carriage (9), a reservoir (10) whose volume interior is divided into two parts by a flexible membrane (15), a part of the tank being connected by a pipe (15) to a vacuum pump (12) mounted on the carriage (9) and the other part being   connected by a pipe (18) to a container (11) for collecting liquids and purged gases.   3.- A collection device according to claim 2 characterized in that the container (11) for collecting purged liquids and gases consists of a container whose lower part is connected to the lower part of the tank (10) and whose upper part is connected to a   venting device (24) for venting gases to the atmosphere.   4. A collection device according to claim 3, characterized in that a filter element is arranged between the   gas and liquid collection vessel and the venting device.   5. A collection device according to any one of the claims 1, 2, 3 and 4, 2 483115   characterized by the fact that the connecting chamber of small size   consists of a glove box whose wall is at least   tially transparent, connectable by means of purge through   flexible lip and clamp.   6. A collection device according to claim 5, characterized   in that the connection chamber contains a device for disconnecting   tamination constituted by a spray boom.